The conjugation of glutathione with herbicides and insecticides is considered to be one of the major detoxification mechanisms of plants. This conjugation is catalysed by a family of multifunctional proteins known as glutathione-s-transferases. Treatment of wheat (Triticum aestivum L. cv. Cumhuriyet-75), barley (Hordeum vulgare L. cv. Kaya), chickpea (Cicer arietinum L. cv. Ispanyol), and lentil (Lens culinaris Medik. cv. Kışlık-kırmızı-51) with the selective herbicides 2,4-D (2,4-Dichloro phenoxyacetic acid) and linuron (N-(3,4-dichlorophenyl)-N´-methoxy-N´-methyl urea), and insecticides parathion methyl (O,O-dimethyl O-(4-nitrophenyl) phosphorothioate) and malathion (S-1,2-bis(ethoxycarbonyl)ethyl O,O-dimethyl phosphorodithioate) caused a progressive increase in glutathione-s-transferase activity in roots and shoots. The maximum increase in enzyme activity was observed in parathion methyl treated wheat roots: 485% of control with a parathion methyl concentration of 1.37 mM. A similar but lower increase in glutathione (GSH) levels was observed for roots and shoots, differing according to the origin and the type of pesticide.

The conjugation of glutathione with herbicides and insecticides is considered to be one of the major detoxification mechanisms of plants. This conjugation is catalysed by a family of multifunctional proteins known as glutathione-s-transferases. Treatment of wheat (Triticum aestivum L. cv. Cumhuriyet-75), barley (Hordeum vulgare L. cv. Kaya), chickpea (Cicer arietinum L. cv. Ispanyol), and lentil (Lens culinaris Medik. cv. Kışlık-kırmızı-51) with the selective herbicides 2,4-D (2,4-Dichloro phenoxyacetic acid) and linuron (N-(3,4-dichlorophenyl)-N´-methoxy-N´-methyl urea), and insecticides parathion methyl (O,O-dimethyl O-(4-nitrophenyl) phosphorothioate) and malathion (S-1,2-bis(ethoxycarbonyl)ethyl O,O-dimethyl phosphorodithioate) caused a progressive increase in glutathione-s-transferase activity in roots and shoots. The maximum increase in enzyme activity was observed in parathion methyl treated wheat roots: 485% of control with a parathion methyl concentration of 1.37 mM. A similar but lower increase in glutathione (GSH) levels was observed for roots and shoots, differing according to the origin and the type of pesticide.